groups

var GroupBSONBuilder = func(param search.SearchParam, searcher *search.MongoSearcher) (object bson.M, err error) {

	gp, ok := param.(*GroupParam)
	if !ok {
		return nil, errors.New("Expected a GroupParam")
	}

	// First get the group
	var groupID string
	if bson.IsObjectIdHex(gp.Code) {
		groupID = bson.ObjectIdHex(gp.Code).Hex()
	} else {
		return nil, fmt.Errorf("Invalid BSON ID: %s", gp.Code)
	}
	var group fhir.Group
	if err := searcher.GetDB().C("groups").Find(bson.M{"_id": groupID}).One(&group); err != nil {
		return nil, err
	}

	if group.Actual != nil && *group.Actual {
		// Return a BSON object (for patient) indicating the ID can be any of those in the group
		var ids []string
		for _, m := range group.Member {
			if m.Entity != nil && m.Entity.Type == "Patient" && m.Entity.ReferencedID != "" {
				ids = append(ids, m.Entity.ReferencedID)
			}
		}
		return bson.M{
			"_id": bson.M{
				"$in": ids,
			},
		}, nil
	}

	info, err := LoadCharacteristicInfo(group.Characteristic)
	if err != nil {
		return nil, err
	}

	if !info.HasConditionCharacteristics && !info.HasEncounterCharacteristics {
		q := search.Query{Resource: "Patient", Query: info.PatientQueryValues.Encode()}
		return searcher.CreateQueryObject(q), nil
	}

	ids, err := resolveGroup(info, searcher)
	if err != nil {
		return nil, err
	}

	return bson.M{
		"_id": bson.M{
			"$in": ids,
		},
	}, nil
}

var GroupParamInfo = search.SearchParamInfo{
	Resource: "Patient",
	Name:     "groupId",
	Type:     "ie.group",
}

var GroupParamParser = func(info search.SearchParamInfo, data search.SearchParamData) (search.SearchParam, error) {
	return &GroupParam{
		TokenParam: *search.ParseTokenParam(data.Value, info),
	}, nil
}

var QueryBSONBuilder = func(param search.SearchParam, searcher *search.MongoSearcher) (object bson.M, err error) {

	qp, ok := param.(*QueryParam)
	if !ok {
		return nil, errors.New("Expected a QueryParam")
	}
	if qp.String != "group" {
		return nil, fmt.Errorf("Unknown _query type: %s", qp.String)
	}
	return bson.M{}, nil
}

var QueryParamInfo = search.SearchParamInfo{
	Resource: "Patient",
	Name:     "_query",
	Type:     "ie.noop",
}

var QueryParamParser = func(info search.SearchParamInfo, data search.SearchParamData) (search.SearchParam, error) {
	return &QueryParam{
		StringParam: *search.ParseStringParam(data.Value, info),
	}, nil
}